The Physostegia virginiana has started to bloom in the garden this week. It is also known by the common names of Obedient Plant and False Dragonhead.
The name Obedient Plant comes from the odd fact that the stems when bent stay put instead of springing back as most plants would.
The true Dragonhead (Dracocephalum) is said to represent the open mouth of a dragon. Physostegia is in a different genus but has similar two-lipped flowers, lobed at the base and the upper lip, resembling fanciful heads of dragons ...and is thus called False Dragonhead